JP4710576B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a reflection-type liquid crystal display device, and more particularly to a liquid crystal display device and a method for manufacturing the same that prevent a short circuit between two metal light-shielding films to improve yield.

  Recently, there is an increasing demand for a projection display device for displaying a video on a large screen, such as a display for displaying a high definition video such as a high-definition video. The projection type display device is roughly classified into a transmission type and a reflection type, and both types are applied with a spatial light modulation unit using an LCD (Liquid Crystal Display) panel as a liquid crystal display device. The readout light is incident on the panel, and the incident light is modulated in units of pixels in correspondence with the video signal so as to obtain projection light.

  Here, the LCD panel has a common transparent film formed on an active matrix substrate on which a switching element such as a thin film transistor and a pixel electrode whose potential is controlled by the switching element are arranged on a semiconductor substrate, and a transparent substrate (glass substrate or the like). An electrode and a liquid crystal sealed between the active matrix substrate and the common transparent electrode, and the potential difference between the common transparent electrode and each pixel electrode is changed for each pixel electrode corresponding to the video signal, The readout light is modulated by controlling the alignment of the liquid crystal.

  Next, the configuration of the liquid crystal display device will be described taking a reflective liquid crystal display device as an example. FIG. 8 is a block diagram of a reflective liquid crystal display device. As shown in FIG. 8, in this liquid crystal display device, pixels Px are arranged in a matrix in the vertical and horizontal directions, and each pixel Px has a signal wiring X extending from the horizontal shift register circuit 2 side for each column. Are connected to the gate wiring Y extending from the vertical shift register circuit 4 side for each row. Each signal wiring X is connected to a video line 8 that supplies a video signal via a video switch 6 (only one is shown in the figure), and an instruction from the horizontal shift register circuit 2 Is switched by.

Each pixel Px holds the potential of the pixel electrode 10, the reflective pixel electrode 10, the transparent electrode 12 common to each pixel Px across the liquid crystal, the switching element 14 that drives the pixel electrode 10, and the pixel electrode 10. Holding capacitor 16. Here, the respective pixel electrodes 10 are arranged in a matrix corresponding to the pixels Px with a pixel gap, which is a slight gap, between the adjacent pixel electrodes 10.
The gate G (see FIG. 9) of the switching element 14 is connected to the gate line Y, the drain D is connected to the signal line X, and the source S is connected to the pixel electrode 10. In FIG. 8, the circuit configuration is shown in some pixels, and the arrangement positions of circuit components are shown in other pixels.

  In this configuration, the video signal from the video line 8 is sequentially supplied by the video switch 6 with the timing shifted, and at the same time, the selection signal is sequentially supplied to the gate wiring Y by shifting the timing, whereby one specific pixel is Will be selected. Then, the input video signal is written in the storage capacitor 16 in the form of electric charges. A potential difference is generated between the pixel electrode 10 and the transparent electrode 12 in accordance with the video signal, and the optical characteristics of the liquid crystal sealed in the meantime are modulated. As a result, since the incident light L is modulated for each pixel Px, reflected by the pixel electrode 10 and output as readout light, unlike the conventional transmissive projector element, the incident light can be used nearly 100%, and has high definition and high brightness. And both.

  Here, the configuration of the pixel Px will be described in more detail. FIG. 9 is a cross-sectional view centered on one pixel of the conventional liquid crystal display device. As shown in the figure, this liquid crystal display device includes a first substrate 24 made of a semiconductor substrate having a plurality of reflective pixel electrodes 10 formed on a surface in a matrix form with a predetermined pixel gap 20 therebetween, and a transparent surface. The electrode 12 is mainly composed of a second substrate 26 which is a transparent substrate formed in common over all pixels, and a liquid crystal 28 sealed between the pixel electrode 10 and the transparent electrode 12. Here, a portion corresponding to one pixel electrode 10 corresponds to one pixel Px.

  The first substrate 24, which is a semiconductor substrate, is configured as an active matrix substrate as follows. That is, the first substrate 24 includes, for example, a silicon substrate 30 which is a semiconductor substrate. On the silicon substrate 30, a MOSFET switching element 14 including a source S, a gate G, and a drain D and a storage capacitor 16 are provided. Are provided side by side. The switching element 14 is provided on the well 32. The switching elements 14 and the storage capacitor 16 are separated from each other by a field oxide film 34. The source S of the switching element 14 and the storage capacitor 16 are connected.

Then, a patterned first wiring layer 38 is formed through an initial interlayer insulating film 36 made of, for example, an SiO ₂ film so as to cover the surfaces of the switching element 14 and the storage capacitor 16. A predetermined thickness, for example, made of Al, interposed between the first wiring layer 38 and the pixel electrode 10 so as to be sandwiched between the first interlayer insulating film 40 and the second interlayer insulating film 44. The first metal light shielding film 42 is patterned and formed. The first metal light-shielding film 42 is provided at least in a region corresponding to the lower part of the pixel gap 20 so as to block intrusion light from the pixel gap 20 on the way. That is, when intrusion light is incident on the drain D and the source S, which are the diffusion electrodes of the switching element 14, photocarriers are generated to cause a leakage current, which causes a fluctuation in the potential of the pixel electrode that is the origin of flicker and burn-in. By providing the first metal light-shielding film 42, a light path (optical path length) is increased to absorb light in the middle.

The pixel electrode 10, the first is insulated from the metal light-shielding film 42 and the pixel electrode 10 is buried wiring formed thereon Symbol first及 beauty second interlayer insulating film 40, 44 46 , 48 are electrically connected to the source S. In the middle of the embedded wirings 46 and 48, a metal film 42A used for forming the first metal light shielding film 42 is interposed.

By the way, as shown in FIG. 9, when the intrusion light L1 that has entered through the pixel gap 20 between the pixel electrodes 10 among the incident light L reaches the diffusion electrodes such as the source S and the drain D as described above, the source S and the drain D has become a PN junction between the well 32, since it is a photo-diode, to cut off the intruding light L1 in developing in order to prevent the occurrence of light carrier reduction It is necessary to let
In this case, as described above, although the first metal light-shielding film 42 is provided, the intrusion light L1 cannot be sufficiently blocked, and a part of the intrusion light L1 reflects inside to perform switching. In some cases, light carriers are generated by reaching the element 14.

In view of this, there has been proposed an invention in which two metal light-shielding films are provided in order to completely block the intrusion light L1 (Patent Documents 1 and 2). Specifically, as shown in FIG. 10, for example, a light shielding insulating film 50 having a predetermined thickness H1 made of, for example, a SiO ₂ film is provided on the upper surface side of the first metal light shielding film 42 shown in FIG. A second metal light shielding film 52 is formed therethrough. The second metal light-shielding film 52 has a gap corresponding to the pixel gap 20 so that incident light is not reflected, and is electrically connected to the corresponding pixel electrode 10 via the embedded wiring 48. It is connected. The thickness H1 of the light shielding insulating film 50 is set to be equal to or less than the wavelength of the incident light (intrusion light L) to prevent the incident light from propagating through the light shielding insulating film 50 while being reflected.

The reflective liquid crystal display device reflects light with a wavelength of 400 nm to 700 nm in the visible light region and performs color display. Therefore, since it is not necessary to use blue light of 400 nm or less, it is not necessary to make light incident on the liquid crystal display device.
Here, if the thickness H1 of the light shielding insulating film 50 is set to 400 nm or less of blue light, the light wave incident on the light shielding insulating film 50 is absorbed by the metal in the vertical direction, or Since the light is reflected, the light shielding effect can be maximized. Naturally, since the first metal light shielding film 42 and the second metal light shielding film 52 need to be insulated, the film thickness H1 of the light shielding insulating film 50 is set within a range of 400 nm or less in consideration of the yield. To do.

Further, since the light shielding insulating film 50 is formed by CVD, it is excellent in in-plane uniformity of film thickness on the wafer as is well known. Therefore, the thickness H1 of the light shielding insulating film 50 between the first metal light shielding film 42 and the second metal light shielding film 52 can be set relatively uniformly. Therefore, it can be created with less variation in the light shielding effect.
For this reason, most of the light entering the switching element 14 from the pixel gap 20 of the pixel electrode 10 can be cut, and a leakage current due to the light can be prevented.

JP 2002-40482 A JP 2004-206108 A

However, as described above, when the thickness H1 of the light-shielding insulating film 50 interposed between the first and second metal light-shielding films 42 and 52 is reduced as described above, these first and second metals. The probability that the light shielding films 42 and 52 are short-circuited is increased. In particular, as shown in FIG. 10, short-circuiting frequently occurs in the corner portion A around the second metal light-shielding film 42. There is a problem that the yield of the product is lowered and the pressure resistance of the pixel electrode 10 is also lowered.
The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a liquid crystal display device and a method for manufacturing the same that can significantly improve the yield of a product by preventing the occurrence of a short circuit between metal light shielding films.

According to a first aspect of the present invention, there is provided a semiconductor substrate having a plurality of reflective pixel electrodes arranged in a matrix with a predetermined pixel gap formed on a surface thereof via an insulating layer, the pixel electrode and a predetermined gap. a counter transparent substrate which transparent electrodes are formed on the surface thereof to have a liquid crystal filled in the predetermined gap, is formed in a region including at least the pixel gap before Symbol insulating layer, said transparent It is formed only on the first metal light-shielding film having a predetermined thickness that blocks intrusion light incident on the pixel gap from the substrate side and is insulated from the pixel electrode, and on the sidewall of the first metal light-shielding film. A sidewall made of an insulating material having a cross-sectional shape that becomes wider in an arc shape from the transparent substrate side toward the semiconductor substrate side, and a surface of the first metal light-shielding film so as to cover the sidewall. The A light shielding insulating film with a thickness of the constant, a liquid crystal display device characterized by having, a second metal light-shielding film formed on a surface of the light shielding insulating film.
In this case, for example, as defined in claim 2, in the region where the first metal light shielding film is formed, the light shielding is provided between the first metal light shielding film and the second metal light shielding film. And the thickness of the light-shielding insulating film interposed between the first metal light-shielding film and the second metal light-shielding film is less than the wavelength of the intrusion light. is there.

According to a third aspect of the present invention, there is provided a semiconductor substrate having a plurality of reflective pixel electrodes arranged in a matrix with a predetermined pixel gap and a switching element for supplying power to the pixel electrodes formed on the surface thereof, the method of manufacturing a liquid crystal display device having a transparent substrate having a transparent electrode formed on its surface facing a said pixel electrodes with a predetermined gap therebetween, and a liquid crystal filled in the prescribed between gap, the semiconductor A first wiring layer forming step of forming a first wiring layer connected to the switching element on the surface of the substrate; and a first insulating layer covering the first wiring layer and covering the entire surface of the semiconductor substrate. A first insulating layer forming step for forming; a first connecting hole forming step for forming a first connecting hole at a predetermined position of the first insulating layer so that a surface of the first wiring layer is exposed; Table of the first insulating layer A first metal light-shielding film having a predetermined pattern shape and a predetermined thickness; and a first gap having a predetermined gap from the first metal light-shielding film and filling the first connection hole. A first metal light-shielding film forming step for forming a second wiring layer connected to the layer; and after forming an insulating film covering the first metal light-shielding film, etching back the insulating film, A side having a cross-sectional shape in which the surface of the metal light-shielding film is exposed and only the side wall of the first metal light-shielding film is widened in an arc shape from the surface side of the first metal light-shielding film to the back side of the opposite side. A sidewall forming step of forming a wall; a light shielding insulating film forming step of forming a light shielding insulating film having a predetermined thickness on a surface of the first metal light shielding film so as to cover the sidewall ; and the light shielding. A predetermined pattern on the surface of the insulating film Forming a second metal light shielding film having a shape, and forming a second insulating layer on the surface of the light shielding insulating film so as to cover the second metal light shielding film. A second insulating layer forming step; a second connecting hole forming step of forming a second connecting hole at a predetermined position of the second insulating layer so that a surface of the second wiring layer is exposed; A pixel electrode forming step of forming a plurality of the pixel electrodes to fill the two connection holes and connect to the second wiring layer so as to be arranged in a matrix with the predetermined pixel gap. This is a method for manufacturing a liquid crystal display device.
In this case, for example, as defined in claim 4, in the light shielding insulating film forming step, the thickness of the light shielding insulating film on the surface of the first metal light shielding film is set from the transparent substrate side to the pixel. The wavelength is less than or equal to the wavelength of the intrusion light incident on the gap.

According to the liquid crystal display device and the method for manufacturing the same according to the present invention, the following excellent operational effects can be exhibited.
By forming a sidewall on the side wall in the peripheral portion of the first metal light shielding film, it is possible to prevent a short circuit between the second metal light shielding film and the product yield. At the same time, the pressure resistance of the pixel electrode can be kept high, and the cost can be reduced by increasing the yield. For this reason, the film thickness of the light shielding insulating film can be made thinner than before.
In addition, light leakage can be reduced and the holding capacitance value can be increased, so that flicker and image sticking can be reduced, and analog characteristics such as crosstalk and feedthrough related to parasitic capacitance can be improved. .

Hereinafter, an embodiment of a liquid crystal display device and a manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view centering on one pixel of a first embodiment of a liquid crystal display device according to the present invention, and FIG. 2 is a partially enlarged view for explaining the operation of a sidewall in the first embodiment of the present invention device. 3 and 4 are process diagrams showing the manufacturing process of the first embodiment of the apparatus of the present invention. In addition, the same code | symbol is attached | subjected about the component same as the component shown in FIGS.

First, the planar structure of the first embodiment of the liquid crystal display device according to the present invention is the same as the structure shown in FIG. The cross-sectional structure is the same as that shown in FIG. 10 except that sidewalls are formed as described below.
That is, as shown in FIG. 1, the liquid crystal display device includes a first substrate 24, which is a semiconductor substrate having a plurality of reflective pixel electrodes 10 formed on a surface in a matrix with a predetermined pixel gap 20 therebetween. , Mainly composed of a second substrate 26 which is a transparent substrate having a transparent electrode 12 formed on the surface in common over all pixels, and a liquid crystal 28 sealed between the pixel electrode 10 and the transparent electrode 12. Has been. Here, a portion corresponding to one pixel electrode 10 corresponds to one pixel Px.

Further, a second metal light-shielding film 52 is formed on the upper surface side of the first metal light-shielding film 42 via a light-shielding insulating film 50 having a predetermined thickness H1 made of, for example, a SiO ₂ film. The second metal light-shielding film 52 has a gap corresponding to the pixel gap 20 so that incident light is not reflected, and is electrically connected to the corresponding pixel electrode 10 via the embedded wiring 48. It is connected. The thickness H1 of the light shielding insulating film 50 is set to be equal to or less than the wavelength of the incident light (intrusion light L) to prevent the incident light from propagating through the light shielding insulating film 50 while being reflected. Further, the thickness H2 of the first metal light shielding film 42 is about 700 nm, and the thickness of the second metal light shielding film 52 is about 70 nm.

  The first substrate 24 is configured as an active matrix substrate as follows. That is, the first substrate 24 includes, for example, a silicon substrate 30 which is a semiconductor substrate. On the silicon substrate 30, a MOSFET switching element 14 including a source S, a gate G, and a drain D and a storage capacitor 16 are provided. Are provided side by side. The switching element 14 is provided on the well 32. The switching elements 14 and the storage capacitor 16 are separated from each other by a field oxide film 34. The source S of the switching element 14 and the storage capacitor 16 are connected.

Then, a patterned first wiring layer 38 is formed through an initial interlayer insulating film 36 made of, for example, an SiO ₂ film so as to cover the surfaces of the switching element 14 and the storage capacitor 16. Between the first wiring layer 38 and the pixel electrode 10, between the first interlayer insulating film 40 that is the first insulating layer and the second interlayer insulating film 44 that is the second insulating layer. A first metal light-shielding film 42 made of, for example, Al having a predetermined thickness interposed so as to be sandwiched is patterned and formed. That is, the first metal light shielding film 42 is provided in the insulating layer. The first metal light-shielding film 42 is provided at least in a region corresponding to the lower part of the pixel gap 20 so as to block intrusion light from the pixel gap 20 on the way. That is, when intrusion light is incident on the drain D and the source S, which are the diffusion electrodes of the switching element 14, photocarriers are generated to cause a leakage current, which causes a potential fluctuation of the pixel electrode that causes flicker and image sticking. By providing the first metal light-shielding film 42, a light path (optical path length) is increased to absorb light in the middle.

  The pixel electrode 10 is insulated from the first metal light shielding film 42, and the pixel electrode 10 is embedded in the embedded wirings 46 and 48 formed in the first and second interlayer insulating films 40 and 44. (Each one is embedded corresponding to the first connection hole and the second connection hole) and is electrically connected to the source S. In the middle of the embedded wirings 46, 48, a metal film used for forming the first metal light shielding film 42, which is a second wiring separated from the first metal light shielding film 42. A metal film 42A as a layer is interposed. The first connection hole is formed by etching after depositing the first interlayer insulating film 40, and the second connection hole is formed by etching after depositing the second interlayer insulating film 44. Is done.

Here, as a feature of the present invention, a sidewall 54 made of an insulating material such as SiO ₂ is formed, for example, in a circular arc shape on the side wall in the periphery of the first metal light shielding film 42. Then, the light shielding insulating film 50 is formed so as to cover the side wall 54. The side wall 54 is continuously formed along the peripheral portion of the first metal light shielding film 42. Such a sidewall 54 can be formed by etching back using an anisotropic etching apparatus such as RIE (reactive ion etching), as will be described later.

  In the illustrated example, the side wall 54A is also formed on the peripheral side wall of the metal film 42A. However, this is inevitably performed by etch back, and the side wall 54A is not particularly necessary. This is because the side wall 54A is electrically connected to the corresponding pixel electrode 10 via the embedded wiring 48. Therefore, in addition to the regular storage capacitor 16 arranged in parallel with the switching element 14, the storage capacitor 16A is also provided in the first and second metal light shielding films 42 and 52 disposed via the light shielding insulating film 50. Will be formed.

The reflection type liquid crystal display device performs color display by reflecting light having a wavelength of 400 nm to 700 nm in the visible light region. Therefore, since it is not necessary to use blue light of 400 nm or less, it is not necessary to make light incident on the liquid crystal display device.
Here, if the thickness H1 of the light shielding insulating film 50 is set to 400 nm or less of blue light, the light wave incident on the light shielding insulating film 50 is absorbed by the metal in the vertical direction, or Since the light is reflected, the light shielding effect can be maximized. Naturally, since the first metal light shielding film 42 and the second metal light shielding film 52 need to be insulated, the film thickness H1 of the light shielding insulating film 50 is set within a range of 400 nm or less in consideration of the yield. To do.

Further, since the light shielding insulating film 50 is formed by CVD, it is excellent in in-plane uniformity of film thickness on the wafer as is well known. Therefore, the thickness H1 of the light shielding insulating film 50 between the first metal light shielding film 42 and the second metal light shielding film 52 can be set relatively uniformly. Therefore, it can be created with less variation in the light shielding effect.
For this reason, most of the light entering the switching element 14 from the pixel gap 20 of the pixel electrode 10 can be cut, and a leakage current due to the light can be prevented.

Next, the operation of the sidewalls 54 and 54A will be described with reference to FIG.
2A is an enlarged view of the peripheral portion of the first metal light shielding film shown in FIG. 10 for comparison, and FIG. 2B is an enlarged view of the peripheral portion of the first metal light shielding film of the device of the present invention. FIG. In an actual apparatus, an antireflection film 60A and a barrier metal 60B made of a TiN film are formed on the upper and lower surfaces of the first metal light shielding film 42, respectively.
As shown in FIG. 2A, in the conventional apparatus, the thickness H1 of the light-shielding insulating film 50 is 400 nm or less (for example, 200 nm) at the corner portion A of the patterned side wall of the first metal light-shielding film 42. Therefore, it can be seen that the second metal light-shielding film 44 is likely to be short-circuited.

This is because the first metal light-shielding film 42 is made of aluminum, the barrier metal 60B (TiN) on the lower surface thereof, and the antireflection film 60A disposed thereon is made of a TiN film. This is because the etching shape differs between aluminum and TiN due to the difference in the metal material to be etched during etching.
As a result, the antireflection film 60A made of a TiN film becomes an eaves shape and the coverage is deteriorated, and the eaves part easily causes a short circuit with the second metal light shielding film 44.

  However, according to the device of the present invention shown in FIG. 2 (B), the sidewall 54 made of an insulating film (oxide film) is formed in the patterned side wall portion B of the first metal light-shielding film 42. Good coverage can be formed without being affected by the reduction in coverage due to the eaves portion 62 of the antireflection film 60A. Therefore, a short circuit between the second metal light-shielding film 44 and the first metal light-shielding film 42 does not occur, and as a result, it is possible to greatly improve the yield reduction and the withstand voltage reduction of the product.

  Furthermore, according to the structure of the present invention, since it is not affected by the coverage reduction due to the eaves portion 62 due to the antireflection film 60A, even if the light shielding insulating film 50 is made thinner, the second metal light shielding film 44 and It is possible to suppress a decrease in yield and a decrease in breakdown voltage due to the short circuit of the first metal light shielding film 42. As a result, light leakage can be further reduced and the holding capacitance value can be increased, thereby reducing flicker and image sticking and improving analog characteristics such as crosstalk and feedthrough related to parasitic capacitance. In addition, higher performance and higher reliability are possible.

A method of manufacturing the liquid crystal display device of the first embodiment will be described with reference to FIGS. First, as shown in FIG. 3A, up to the first metal light-shielding film 42 is formed by repeating a normal method, that is, film formation and etching.
Next, as shown in FIG. 3B, an oxide film 64 made of a SiO ₂ film is formed by a CVD method with a thickness of, for example, 500 nm.

  Next, as shown in FIG. 3C, the entire surface is etched back by an anisotropic etching apparatus such as RIE. At this time, since the oxide film 64 is etched from the upper surface by etch back, the oxide film 64 formed on the side wall portion of the first metal light-shielding film 42 is formed thick in the height direction. Therefore, the sidewall 54 is formed. A sidewall 54A is also formed on the side wall portion of the metal film 54A. At this time, the anisotropic etching is set so that the etching is finished when most of the oxide film disappears by the end point, so that the oxide film 64 can be formed to remain as the sidewalls 54 and 54A. Is possible.

Next, as shown in FIG. 3D, a light-shielding insulating film 50 made of a SiO ₂ film is formed to a thickness of 200 nm. At this time, the light-shielding insulating film 50 is formed to 200 nm on the sidewall 54 formed on the side wall portion of the first metal light-shielding film 42 and the other sidewall 54A. At this time, since the side walls 54 and 54A are already formed on the side walls of the first metal light-shielding film 42 and the metal film 42A, coverage by the eaves portion 62 (see FIG. 2) of the antireflection film 60A made of TiN. There is no impact on the decline.
Next, as shown in FIG. 3E, a second metal light shielding film 52 is formed by forming a TiN film of 70 nm and patterning it.

Next, as shown in FIG. 4A, an oxide film made of a SiO ₂ film is formed to a thickness of about 1400 nm, and is flattened using a CMP (Chemical Mechanical Polishing) method or the like to a thickness of 700 nm. Two interlayer insulating films 44 are formed.
Next, as shown in FIG. 4B, a connection hole 66 for connecting the first metal light shielding film 42, the second metal light shielding film 52, and the pixel electrode 10 is formed by patterning and etching.

Next, as shown in FIG. 4C, tungsten is formed using a CVD method, and buried wiring 48 is formed by embedding tungsten in the connection hole 66 using etch back.
Next, as shown in FIG. 4D, a pixel electrode is formed by sputtering, patterning, etching, or the like.
Through the above steps, the first substrate 24 is substantially completed. Thereafter, as shown in FIG. 1, the first substrate 24 and the second substrate 26 having the transparent electrode 12 are opposed to each other, and a liquid crystal 28 is sealed between the two substrates, whereby the liquid crystal display device is obtained. It will be completed.

  Next, a configuration including the peripheral portion of the liquid crystal display device formed as described above will be described. FIG. 5 is a diagram showing a state including a peripheral portion of the liquid crystal display device, FIG. 5A shows a perspective view of the main body of the liquid crystal display device, and FIG. 5B shows a flexible printed wiring board on the main body. The top view of the connected state is shown. As shown in FIG. 5, a transparent second substrate 26 is connected on a first substrate 24 made of a silicon substrate with a liquid crystal (not shown) interposed therebetween in a peripheral seal region 70. Here, a portion where the pixels Px are arranged is a pixel region 72. In addition, a driver circuit 74 including the horizontal shift register circuit 2 and the vertical shift register 4 is formed in the peripheral portion of the pixel region 72. The seal area 70 is provided outside the driver circuit 74, and a seal material and spacer balls are applied thereto. The pixel region 72 has a spacerless structure in which a liquid crystal gap is created in the seal region 70 without using a spacer.

The transparent electrode formed on the transparent second substrate 26, a conductive paste is piled on the counter contact 76 formed on the first base plate 24, a second substrate 26 first substrate 24 Are connected when they are bonded and fixed by a sealing material. The counter contact 76 is wired to an external connection terminal 78, and a predetermined voltage can be applied from the external connection terminal 78.
As shown in FIG. 5B, a flexible printed wiring board 80 for supplying a signal from the outside is connected to the external connection terminal 78, and the external signal is provided on the flexible printed wiring board 80. It is input from the external input terminal 82.

<Second embodiment>
Next, a second embodiment of the method of the present invention will be described.
In the first embodiment, the pixel electrode 10 and the metal film 42A are directly electrically connected by the embedded wiring 48. In the second embodiment, the pixel electrode 10 and the metal film 42A are connected. Is configured to be electrically connected via the embedded wiring 48 and the second metal light-shielding film 12.
6 and 7 are process diagrams showing the manufacturing process of the second embodiment of the method of the present invention as described above. The same components as those shown in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof is omitted.

  First, the steps shown in FIGS. 3A to 3D are similarly applied to the second embodiment, and the sidewalls are formed. Then, if the light shielding insulating film 50 is formed on the entire surface as shown in FIG. 3D, the light shielding insulating film 50 is patterned and etched to form a metal as shown in FIG. 6A. A through hole 84 is formed in a portion corresponding to the film 42A. The through hole 84 is a hole for connecting the metal film 42A and the second metal light-shielding film 52 (see FIG. 1) to be formed therefrom. The metal film 42 </ b> A is exposed at the bottom of the through hole 84.

  The subsequent steps are substantially the same as the steps shown in FIGS. 3 (E) to 4 (D). That is, as shown in FIG. 6B, a second metal light-shielding film 52 is formed by forming a TiN film of 70 nm and patterning it. At this time, the second metal light shielding film 52 and the metal film 42A are connected.

Next, as shown in FIG. 6C, an oxide film made of an SiO ₂ film is formed to a thickness of about 1400 nm, flattened using a CMP method or the like to a thickness of 700 nm, and the second interlayer insulating film 44 is formed.
Next, as shown in FIG. 7A, a connection hole 66 for connecting the second metal light-shielding film 52 and the pixel electrode 10 is formed by patterning and etching.

Next, as shown in FIG. 7B, tungsten is formed using a CVD method, and buried wiring 48 is formed by embedding tungsten in the connection hole 66 using etch back.
Next, as shown in FIG. 7C, a pixel electrode is formed by sputtering, patterning, etching, or the like. Thereby, the pixel electrode 10 is connected to the metal film 42 </ b> A via the embedded wiring 48 and the second metal light shielding film 52.
Through the above steps, the first substrate 24 is substantially completed. Thereafter, as shown in FIG. 1, the first substrate 24 and the second substrate 26 having the transparent electrode 12 are opposed to each other, and a liquid crystal 28 is sealed between the two substrates, whereby the liquid crystal display device is obtained. It will be completed.

In this way, by forming the sidewall 54 on the side wall of the peripheral portion of the first metal light shielding film 42, it is possible to prevent the occurrence of a short circuit between this and the second metal light shielding film 52. The product yield can be maintained at a high level, and the pressure resistance of the pixel electrode 10 can be maintained at a high level, so that the cost can be reduced by increasing the yield. For this reason, the film thickness of the light shielding insulating film 50 can be made thinner than before.
In addition, light leakage can be reduced and the holding capacitance value can be increased, so that flicker and image sticking can be reduced, and analog characteristics such as crosstalk and feedthrough related to parasitic capacitance can be improved. .

As a result, for example, the area of the same display region can be packed with more pixels than in the conventional device, so that high definition can be realized, and the performance of the liquid crystal display device can be greatly improved.
In addition, if a reflective liquid crystal display device having the same number of pixels as the conventional one is produced using the present invention, the screen size can be reduced, so that the chip size is reduced. For example, the reflection cut out from one wafer size. Since the number of chips for the liquid crystal display device increases, the cost can be significantly reduced. In addition, if the screen size of the reflective liquid crystal display device is reduced, the optical system and the lamp can be reduced, so that the projector system can be reduced in size, cost and weight at the same time. Therefore, significant performance enhancement is possible.

1 is a cross-sectional view centering on one pixel of a first embodiment of a liquid crystal display device according to the present invention. It is the elements on larger scale for demonstrating the effect | action of the sidewall in 1st Example of this invention apparatus. It is process drawing which shows the manufacture process of 1st Example of this invention apparatus. It is process drawing which shows the manufacture process of 1st Example of this invention apparatus. It is a figure which shows the state also including the peripheral part of a liquid crystal display device. It is process drawing which shows the manufacturing process of 2nd Example of this invention method. It is process drawing which shows the manufacturing process of 2nd Example of this invention method. 1 is a block configuration diagram of a reflective liquid crystal display device. FIG. It is sectional drawing represented centering on one pixel of the conventional liquid crystal display device. It is a figure which shows the optical path of the intrusion light in one pixel of the conventional liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Pixel electrode, 12 ... Transparent electrode, 14 ... Switching element, 16 ... Retention capacity, 20 ... Pixel gap, 24 ... 1st board | substrate (semiconductor substrate), 26 ... 2nd board | substrate (transparent substrate), 28 ... Liquid crystal , 36 ... initial interlayer insulating film, 38 ... first wiring layer, 40 ... first interlayer insulating film (first insulating layer), 42 ... first metal light shielding film, 42A ... metal film (second wiring) Layer) 44 ... second interlayer insulating film (second insulating layer), 50 ... light shielding insulating film, 52 ... second metal light shielding film, 54 ... side wall, 66 ... connection hole, L ... incident light, L1 ... Intrusion light, Px ... Pixels.

Claims (4)

A semiconductor substrate in which a plurality of reflective pixel electrodes arranged in a matrix with a predetermined pixel gap are formed on the surface via an insulating layer;
A transparent substrate on the surface of which a transparent electrode facing the pixel electrode with a predetermined gap is formed;
A liquid crystal filled in the predetermined gap ;
Wherein is formed in a region including at least the pixel gaps in the insulating layer, the first having a predetermined thickness, which is insulated from the pixel electrode while blocking the intrusion light incident on the pixel gap from the transparent substrate side Metal shading film of,
A side wall made of an insulating material having a cross-sectional shape that is formed only on the side wall of the first metal light-shielding film and is arcuately widened from the transparent substrate side toward the semiconductor substrate side ;
A light-shielding insulating film having a predetermined thickness formed on the surface of the first metal light-shielding film so as to cover the sidewall ;
A second metal light shielding film formed on the surface of the light shielding insulating film;
A liquid crystal display device comprising: In the region where the first metal light-shielding film is formed, only the light-shielding insulating film is interposed between the first metal light-shielding film and the second metal light-shielding film, and 2. The liquid crystal display according to claim 1, wherein a thickness of the light shielding insulating film interposed between the first metal light shielding film and the second metal light shielding film is equal to or less than a wavelength of the intrusion light. apparatus. A semiconductor substrate having a plurality of reflective pixel electrodes arranged in a matrix with a predetermined pixel gap and a switching element for supplying power to the pixel electrode formed on a surface thereof, and a predetermined gap between the pixel electrode and the predetermined gap. In a method for manufacturing a liquid crystal display device, comprising: a transparent substrate having a transparent electrode formed on the surface thereof and a liquid crystal filled in the predetermined gap;
A first wiring layer forming step of forming a first wiring layer connected to the switching element on the surface of the semiconductor substrate;
A first insulating layer forming step of covering the first wiring layer and forming a first insulating layer over the entire surface of the semiconductor substrate;
A first connection hole forming step of forming a first connection hole so that a surface of the first wiring layer is exposed at a predetermined position of the first insulating layer;
A first metal light-shielding film having a predetermined pattern shape and a predetermined thickness on the surface of the first insulating layer, and having a predetermined gap with the first metal light-shielding film and the first connection hole Forming a first metal light-shielding film forming a second wiring layer connected to the first wiring layer,
After forming the insulating film covering the first metal light shielding film, the insulating film is etched back to expose the surface of the first metal light shielding film and to the first metal light shielding film only on the side wall. A sidewall forming step of forming a sidewall having a cross-sectional shape that becomes wider in an arc shape from the front surface side of the metal light shielding film to the opposite back surface side ;
A light shielding insulating film forming step of forming a light shielding insulating film having a predetermined thickness on the surface of the first metal light shielding film so as to cover the sidewall ;
A second metal light-shielding film forming step of forming a second metal light-shielding film having a predetermined pattern shape on the surface of the light-shielding insulating film;
A second insulating layer forming step of forming a second insulating layer on the surface of the light shielding insulating film so as to cover the second metal light shielding film;
A second connection hole forming step of forming a second connection hole so that a surface of the second wiring layer is exposed at a predetermined position of the second insulating layer;
A pixel electrode forming step of forming a plurality of the pixel electrodes that fill the second connection holes and connect to the second wiring layer so as to be arranged in a matrix with the predetermined pixel gap;
A method for manufacturing a liquid crystal display device, comprising:   In the light shielding insulating film forming step, the thickness of the light shielding insulating film on the surface of the first metal light shielding film is set to be equal to or less than the wavelength of the intrusion light incident on the pixel gap from the transparent substrate side. The method of manufacturing a liquid crystal display device according to claim 3.

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